The class Combined2c defines the the residual error variance according
to the formula g(sigma_inter, sigma_slope, c_error, f(x, theta)) = sigma_inter^2 + sigma_slope^2 * f(x,theta)^(2 * c_error)
Combined2c objects
are typically created by calls to Combined2c and contain the following slots that are heritated
from the class ModelError:
.Object:An object of the class ModelError
sigma_inter:A numeric value giving the sigma inter of the error model.
sigma_slope:A numeric value giving the sigma slope of the error model.
c_error:A numeric value giving the exponant c of the error model.